Device for permanent waving of hair



Oct. 17, 1950 c. SCHMIDT DEVICE FOR PERMANENT WAVING OF HAIR 2 Shets-Sheet 1 M Sexu 9 Filed April 2, 1947 Oct. 17, 1950 c, s M 2,526,283

DEVICE FOR PERMANENT WAVING OF HAIR Filed April 2, 1947 2 Sheets-Sheet 2 i ate'nted Oct. 17, 1950 Christian Schmidt, Copenhagem'Denma'rk, assigner to Hcnning Windfeld "Madsen, ZCOpenhagen, Denmark Application April 2, 1947, SeIiaI N O." 738,877 In Sweden August 6,1945

Claims.

e @1 This invention relates to permanent waving of hair andmore particular to a novel and useful apparatus for-'the purpose referred to.

One object ofthe invention is to provide an apparatus of 'the kind refe'rred to, which is utilizing high frequency current for'heating and cooking thehair, and whichis more reliable in opera- 7 tion than corresponding apparatus previously known.

*An otherobject of the invention is to provide an apparatus of the kind referred to which is more simple infope'ration than known before.

Further'objects of the invention are to provide an apparatus of the kind mentioned which needs no separate adjustmentfor each separate coiled tress, because the apparatus itself automatically adjustsfthe quantity of energy out in every tress. The new construction of thelapparatus also elimihates the risk of burning the tress in case of unskilled operation or at any event overloading the tressexposed to'the cooking so that also the risk of'getting negro-curling as often happen ing in oldfashioned permanent waving is completely avoided.

In order more ma to explain the invention,

reference-will now be made to the drawing,

wherein Figure l is a diagrammatic view of an illustrative embodiment of the present invention including an oscillating circuit of high frequency current,

Figure 1a is a side view of the unit including "the oscillator shown in Figure 1,

Figures 2 and 3 are sectional views of coil curl heating pin and clamp, and

Figures 4 and 5 are a sectional and plan view of a separating plate used between the head and the pin shown in Figures 2 and 3.

Referring to Figure'l a transformer I is provided with a primary 2 having a number of'sec tions for the'purpose of connecting the apparatus to the usual supply mains 3 in case ofdifferent main voltages. 4 is the main switch for switching on or off the entire apparatus. In "the following the main is supposed to be of the A. C.

type such as 110 volts at 60 cycles.

This transformer is provided with a secondary 5, from which the voltage is rectified in two diodes V1 and V2 and thereby delivering the anode current to two push-pull coupled oscillator tubes V3 and V4. The transformer I is also provided with two more secondar windings 1.6 :and 1 adapted to energize the filaments of the :rectifiers V1 and V2 and the oscillators V3 and/V4 respectively. Atthe middleof transformer wind- -ing 5 is provided from a point 8 a lead :9 'to the one end of the'filament llllandll in the tubes V3 and V4 through a meter A and a shunt resist "ance R3. Moreoverthe'lead-S connectsithetransformer-middle at 8 with thexgrids l2. and i3 of the oscillator tubes'Vs and-V4 through resistances R1 and R2 and also with the plate circuitof the oscillator'through alea'd' ZU toa point between two condensers-4 8 andl-9,-which are connected in serieswith other condensers l6 and H across the inductance 22.

The point between the condensers l1 and I8 respectively It and i9 are through leads l5 and 14 respectively connected with a grid of the oscillator tubes; *Anode current for the oscillator valves is provided througha lead 32 atthe middle '23 of the'self inductance 22.

The'condens'ers I6, ll, IB and l9and the inductance 22 are so matched as to produce oscillations in the circuit of the constantfrequency preferably at a short wave-length below 100 :m.

The inductance :22 is forming a primar of a transforme 24 :having a secondary windingi25 forming an invariable aperiodic secondary cirwit, to which areconnected terminals28 and 29, the terminal 28 being of the bushingtype while the terminal 29 is of the pin type.

The oscillator-shown diagrammaticallyin Figure 1 is mounted in a casing H of the permanent waving machine'mou-nted on wheels 10! and I02.

The leads 26 and 21 from the aperiodic oscillator secondary are led through a tube 103 having a horizontal projection I04, which at the outer-end i bent down.

The high frequency current from the oscillator is used for permanent waving of the hair by passing directly through the hair, which in advance is moistened with a suitable permanent wave fluid. For this purpose the moistened hair isapplied between two electrodes 36 and 39 to which the high frequency current is applied.

The electrode 36 consists merely of a metallic pin upon which the hair is wound up. At the ends the pin rig-provided with contacts 34 and 3 of the normal pin type to be connected with the bushing 30 of the contact 28.

The electrode 39 consists of a clamp of two parts 39 and 40 connected by means of a pin mounted in projections 4| and 42 of the clamp parts and surrounded by a spring 46 having the ends 41 and 48 lying against the inner side of the finger grips 43 and 44 of the clamp. In the one finger grip 44 is provided a groove 45 for the purpose of combining the 'pin 3| on the contact 29 with a clamp electrode merely by engaging the pin in the groove 45 between the spring end 41 and this part of the finger grip. v

When using the apparatus it will be practical to apply some sort of screen between the head and the pin clamp in order to avoid the cooking moisture from burning the head.

A screen for this purpose is shown in the Fig ures 4 and 5. A screen consists of two plates 5| and 52, at the one end mounted in a common transverse piece 5!! simultaneously forming the support for the pin and clamp in the one end. The screen plate 5| is fixed by means of a rivet at the transverse piece, while the screen plate 52 is pivotably mounted by means of the other rivet. At the other end of the screen plate is mounted a similar transverse piece which by means of a rivet 63 is pivotably connected with the screen plate 5|. The transverse piece at this end is provided with an inclined slot 61 adopted to co-operate with a pin, for instance, also in form of a rivet to lock the two parts of the screen together, when the hair is wound up on the pin 36, and the two screen plates 5| and 52 are provided with rubber or the like on the edges.

The transverse piece at the ends are also shown in Figure 4 provided with upward projections 51 and 56 forming a circular support 58 for bushings 31 and 38 on the ends of the pin 36.

By means of the new apparatus there is obtained the advantage that no time is wasted by tuning the secondary circuit to resonance for each separate coiled tress, the device supplying immediately the correct quantity of energy to each tress. This energy may be adjusted once and for all by the ratio between the number of turns of the tuning coil and the secondary winding so that the treatment is intensified and simplified at the same time as the risk of burning the tress in the case of unskilled operation of the device is totally excluded.

Experiments have shown that the resistance of a tress of hair soaked with permanent wave fluid is 20-50 ohms according to the size of the tress, and it has further been found that a current of 2-5 amperes at a voltage of 100 volts requires an average time of cooking of about A minute which in practice is suificient for obtaining a satisfactory permanent wave.

The consistency of the hair being, however, different with diiferent persons, it may sometimes be convenient to use a somewhat longer time of cooking, e. g. l-1 minutes and instead of adjusting the energy once and for all, it may be convenient to provide for variation of the energy and frequency for the time of cooking. In the device of the kind referred to, this may be achieved in a very simple manner by varying the voltage for example. A lower voltage affords less current and a longer time of cooking so that the degree of the permanent wave obtained may be varied.

It should finally be pointed out that the device will also be more simple and less expensive in construction because the resonance tuning is 4 avoided. Likewise, the device need not operate at any definite frequency so that it may consequently be constructed for operation at a frequency which involves no risk of disturbances or other inconveniences.

If it is desired to vary the cooking time for varying the degree of the permanent wave obtained, this may be accomplished in a very simple manner by varying the voltage of the secondary circuit or alternatively the current may be varied, e. g. by inserting a resistance in the secondary circuit.

What I claim is:

1. In a hair waving apparatus, in combination, a primary oscillator circuit, an aperiodic secondary high frequency circuit fixedly inductively coupled to said primary circuit, hair curling and heating means comprising two substantially concentric contacts separated from each other to provide an annular chamber therebetween for receiving and clamping in said chamber a moistened coiled hair tress, said contacts including terminals thereon arranged to be removably interconnected to said secondary circuit for passing high frequency current through said hair.

2. In a hair waving apparatus, in combination, a primary oscillator circuit, an aperiodic secondary high frequency circuit fixedly inductively coupled to said primary circuit, hair curling and heating means comprising a conductive pin arranged to be surrounded by a coiled moistened hair tress and having a terminal, a conductive clamp normally adjacent said pin for gripping the exterior of said tress and having a terminal, said pin and clamp being separated by said hair tress and arranged to pass current through said hair when said terminals are connected to a circuit, and at least one pair of connectors associated with said secondary circuit removably engageable with said terminals for feeding high frequency current therebetween.

3. In a hair waving apparatus, in combination, a primary oscillator circuit, an aperiodic secondary high frequency circuit fixedly inductively coupled to said primary circuit, hair curling and heating means comprising two normally adjacent electric contacts each having a terminal, one of said contacts including a pin arranged to be surrounded by a moistened coiled hair tress, the other contact including a pair of semi-cylindrical parts spring biased to be normally in abutment substantially to complete a tube closely sur rounding said hair tress for clamping the same between said contacts to constitute the sole electric connection intermediate the contacts, and at least one pair of connectors associated with said secondary circuit and removably engageable with said terminals for feeding high frequency current therebetween.

4. In a method of permanent hair waving by high frequency currents, the steps comprising, coiling and moistening a hair tress, clamping the said tress between two current-free contacts in close proximity to the interior and exterior surfaces of said coiled tress, and then passing between said contacts for a predetermined period of time current of high frequency having a wave length of about m. and about 100 volts and from 2 to 5 amperes.

5. In a method of permanent hair waving by high frequency currents, the steps comprising, coiling and moistening a hair tress, clamping the said tress between two current-free contacts in close proximity to the interior and exterior surfaces of said coiled tress, and then passing between said contacts for a predetermined period .of time current of high frequency having a wave length of about 100 m. and about 100 volts and from 2 to 5 amperes, while simultaneously coil- 'ing a second hair tress between two other contacts, thereafter interrupting the current between said first contacts and passing the same through said second contacts for a like time period.

CHRISTIAN SCHMIDT.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 6 UNITED STATES PATENTS Name Date Whitman Nov. 15, 1938 Durham et a1 Oct. 31, 1939 Keller Nov. 7, 1939 Gulliksen June 2, 1942 FOREIGN PATENTS Country Date Great Britain July 3, 1947 Sweden May 13, 1947 Australia Oct. 1, 1936 Certificate of Correction Patent No. 2,526,283 October 17, 1950 CHRISTIAN SCHMIDT It is hereby certified that error appears in the above numbered patent requiring correction as follows: I

In the heading to the printed specification, lines 6 and 7, strike out Application April 2, 1947, Serial No. 7 38,877 In Sweden August 6, 1945 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oifice. Signed and sealed this 6th day of February, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,526,283 October 17, 1950 CHRISTIAN SCHMIDT It is hereby certified that error appears in the above numbered patent requiring correction as follows:

In the heading to the printed specification, lines 6 and 7, strike out Application April 2, 1947, Serial N 0. 738,877 In Sweden August 6, 1945;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 6th day of February, A. D. 1951.

THOMAS F. MURPHY,

Assistant Gammz'ssz'oner of Patents. 

